A heroin addict who bludgeoned to death a 92-year-old war veteran in his own home has been jailed for at least 20 years.

Jurors at Wolverhampton Crown Court took just four hours to unanimously convict Charlotte Frazier-Doody of the murder of Dunkirk hero Bill Davis, who served in the Royal Navy throughout World War Two.

Jailing the mother-of-three for life, Judge John Warner described the killing in Willenhall, near Walsall, as a savage, ferocious and harrowing attack on a frail and vulnerable victim.

Mr Davis, a great-grandfather who lived independently despite his age, was beaten to death a few days after his 92nd birthday at his home in Hobley Street, Willenhall, in April.

Frazier-Doody, who lived in the same street, told her trial she had played no role in Mr Davis's death and had instead cooked him a meal.

The 36-year-old killer, who was also addicted to crack cocaine, used a heavy weapon - possibly a saucepan - to kill Mr Davis, who was awarded nine medals during the Second World War.

Jurors heard Mr Davis rose to the rank of petty officer as he served on Arctic convoys, took part in the Relief of Malta and fought against the Japanese in the Pacific.

Passing sentence on Frazier-Doody, Judge Warner said Mr Davis had been "savagely beaten to death" with a substantial object in what should have been the safety and security of his own home.

Mr Davis had either been attacked while on the floor, the judge said, or the attack had continued after he was knocked to the ground.

Forensic evidence proved Mr Davis, who died from multiple head and brain injuries, had grabbed a clump of Frazier-Doody's hair as he tried to defend himself.

A two-week trial also heard investigators recovered "billion-to-one" DNA evidence from the scene, including a mixed bloodstain matching both Frazier-Doody and Mr Davis.

The judge told Frazier-Doody: "In my judgment, the motive for this frenzied attack remains a mystery.

"There are no signs that any of the easily-available money was taken.

"Only two people know the true circumstances of what happened on that day - one of them is no longer with us and you have not provided any information."

Charlotte Frazier-Doody was found guilty of the veteran's murder

Neighbours found Mr Davis in his home with severe head injuries from which he subsequently died.

Commenting after sentence was passed, Martin Lindop, sector Crown prosecutor for the West Midlands Crown Prosecution Service, said Mr Davis was extremely independent, but trusted his neighbours, who would always assist him when he needed any help.

Mr Lindop said: "On the afternoon of April 1st, 2012, neighbours heard banging from Mr Davis' house. They went to investigate, but initially did not find anything.

"Later that afternoon they went back to his house, used a key that one of them had been given previously, went inside and found Mr Davis lying in a pool of blood.

"He had multiple head injuries, which an expert has said were caused by repeated blows using a heavy object. Paramedics were unable to revive him."

Mr Lindop added: "Our thoughts are today with the family and friends of Mr Davis and I hope that the outcome of today's trial will go some way to help them to deal with their loss."

In a statement issued by West Midlands Police, Detective Sergeant Rob Bastin, the senior investigating officer, said: "Mr Davis saw action during the Dunkirk evacuation and was involved in the relief of Malta.

"He served with distinction throughout Europe and was 150 miles off the coast of Japan when the atomic bomb was dropped on Hiroshima. He returned from every conflict unscathed."

Det Sgt Bastin added: "How tragic, that after he fought for many years to ensure the safety of every person in this country, he died in his own home, a place where he should have been safe.

"It's difficult to find the words to describe how evil and calculated this woman has been."

Bill Davis as a young man

Thomas Davis, Bill's son also paid tribute to his father after the verdict was returned.

"My father was a well-respected and likeable man who never did anyone any harm," he said.

"He loved his family and when my mum died in 2006 he was devastated after 63 years of marriage.

"He also lost my sister in 2008 which broke his heart, but he carried on.

"Dad never spoke a lot about his war service. The details came out in dribs and drabs over the years but his medals speak for themselves.